1. Field of the Invention
Disclosed embodiments relate to a rotary electric machine.
2. Description of the Related Art
Conventionally, there is known an electric motor (rotary electric machine) having a rotor core (see, e.g., Japanese Patent Laid-open Publication No. H1-286758).
Japanese Patent Laid-open Publication No. H1-286758 discloses an electric motor (rotary electric machine) including a rotor core having a plurality of permanent magnets. In this motor, the permanent magnets are arranged at predetermined intervals in a circumferential manner on the outer periphery of the rotor core. Further, the rotor core between the adjacent permanent magnets is formed in a shape of protrusion. That is, the permanent magnets and the protruding portions of the rotor core are alternately arranged one by one.
Thus, it is configured to obtain a magnet torque between the permanent magnet and winding provided in a stator, and a reluctance torque between the rotor core and the winding provided in the stator. Also, the reluctance torque is increased or decreased in response to a difference (Ld−Lq) between the d-axis inductance (Ld) and the q-axis inductance (Lq). Herein, the d-axis means an axis is in a direction of a main magnetic flux, and the q-axis means an axis is in a direction electrically perpendicular to the d-axis.